package server;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * Minicat的主类
 */
public class Bootstrap {

    /**定义socket监听的端口号*/
    private int port = 8080;

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }


    public Mapper mapper=new Mapper();
    /**
     * Minicat启动需要初始化展开的一些操作
     */
    public void start() throws Exception {

        // 加载解析相关的配置，web.xml
        //loadServlet();

        initServices();

        // 定义一个线程池
        int corePoolSize = 10;
        int maximumPoolSize =50;
        long keepAliveTime = 100L;
        TimeUnit unit = TimeUnit.SECONDS;
        BlockingQueue<Runnable> workQueue = new ArrayBlockingQueue<>(50);
        ThreadFactory threadFactory = Executors.defaultThreadFactory();
        RejectedExecutionHandler handler = new ThreadPoolExecutor.AbortPolicy();


        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(
                corePoolSize,
                maximumPoolSize,
                keepAliveTime,
                unit,
                workQueue,
                threadFactory,
                handler
        );





        /*
            完成Minicat 1.0版本
            需求：浏览器请求http://localhost:8080,返回一个固定的字符串到页面"Hello Minicat!"
         */
        ServerSocket serverSocket = new ServerSocket(port);
        System.out.println("=====>>>Minicat start on port：" + port);

        /*while(true) {
            Socket socket = serverSocket.accept();
            // 有了socket，接收到请求，获取输出流
            OutputStream outputStream = socket.getOutputStream();
            String data = "Hello Minicat!";
            String responseText = HttpProtocolUtil.getHttpHeader200(data.getBytes().length) + data;
            outputStream.write(responseText.getBytes());
            socket.close();
        }*/


        /**
         * 完成Minicat 2.0版本
         * 需求：封装Request和Response对象，返回html静态资源文件
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            response.outputHtml(request.getUrl());
            socket.close();

        }*/


        /**
         * 完成Minicat 3.0版本
         * 需求：可以请求动态资源（Servlet）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            // 静态资源处理
            if(servletMap.get(request.getUrl()) == null) {
                response.outputHtml(request.getUrl());
            }else{
                // 动态资源servlet请求
                HttpServlet httpServlet = servletMap.get(request.getUrl());
                httpServlet.service(request,response);
            }

            socket.close();

        }
*/

        /*
            多线程改造（不使用线程池）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket,servletMap);
            requestProcessor.start();
        }*/



        System.out.println("=========>>>>>>使用线程池进行多线程改造");
        /*
            多线程改造（使用线程池）
         */
        while(true) {

            Socket socket = serverSocket.accept();
            //RequestProcessor requestProcessor = new RequestProcessor(socket,servletMap);
            //requestProcessor.start();
            WebAppProcessor webAppProcessor = new WebAppProcessor(socket, mapper);
            webAppProcessor.start();
           //threadPoolExecutor.execute(webAppProcessor);
        }



    }


    private Map<String,HttpServlet> servletMap = new HashMap<String,HttpServlet>();

    /**
     * 加载解析web.xml，初始化Servlet
     */
    private void loadServlet() {
        InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("web.xml");
        SAXReader saxReader = new SAXReader();

        try {
            Document document = saxReader.read(resourceAsStream);
            Element rootElement = document.getRootElement();
            List<Element> selectNodes = rootElement.selectNodes("//servlet");
            for (int i = 0; i < selectNodes.size(); i++) {
                Element element =  selectNodes.get(i);
                // <servlet-name>lagou</servlet-name>
                Element servletnameElement = (Element) element.selectSingleNode("servlet-name");
                String servletName = servletnameElement.getStringValue();
                // <servlet-class>server.LagouServlet</servlet-class>
                Element servletclassElement = (Element) element.selectSingleNode("servlet-class");
                String servletClass = servletclassElement.getStringValue();


                // 根据servlet-name的值找到url-pattern
                Element servletMapping = (Element) rootElement.selectSingleNode("/web-app/servlet-mapping[servlet-name='" + servletName + "']");
                // /lagou
                String urlPattern = servletMapping.selectSingleNode("url-pattern").getStringValue();
                servletMap.put(urlPattern, (HttpServlet) Class.forName(servletClass).newInstance());

            }



        } catch (DocumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

    }


    private void initServices(){
        InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("server.xml");
        SAXReader saxReader = new SAXReader();
        try {
            Document document = saxReader.read(resourceAsStream);
            Element rootElement = document.getRootElement();
            List<Element> selectNodes = rootElement.selectNodes("//Service");
            for (int i = 0; i <selectNodes.size() ; i++) {
                Element element =  selectNodes.get(i);
                List<Element> connetorElements = element.selectNodes("Connetor");
                for (int j = 0; j <connetorElements.size() ; j++) {
                    Element connetorElement =  connetorElements.get(j);
                    int port = Integer.parseInt(connetorElement.attributeValue("port"));
                    List<Element> hostElements = element.selectNodes("//Host");
                    for (int k = 0; k <hostElements.size() ; k++) {
                        Element hostElement =  hostElements.get(k);
                        String name = hostElement.attributeValue("name");
                        String appBase = hostElement.attributeValue("appBase");
                        initWrapper("D:"+appBase);
                        mapper.addMappedHost(name,mapper.contexts);
                        mapper.hostMap.put(port,mapper.hosts);
                    }

                }

            }
        } catch (DocumentException | IllegalAccessException | InstantiationException e) {
            e.printStackTrace();
        }
    }

    public void initWrapper(String path) throws IllegalAccessException, InstantiationException {
        File pack=new File(path);
        File[] files = pack.listFiles();

        for (File file : files) {
            if (file.isDirectory()) {
                if(!file.getName().equals("server")){
                    initWrapper(path+"/"+file.getName());
                }
            } else if (file.getName().equals("web.xml")) {
                String webXmlPath = path + "/" + file.getName();
                SAXReader saxReader = new SAXReader();
                File webXml=new File(webXmlPath);
                try {
                    Document document = saxReader.read(webXml);
                    Element rootElement = document.getRootElement();
                    List<Element> selectNodes = rootElement.selectNodes("//servlet");
                    for (int i = 0; i < selectNodes.size(); i++) {
                        Element element =  selectNodes.get(i);
                        // <servlet-name>lagou</servlet-name>
                        Element servletnameElement = (Element) element.selectSingleNode("servlet-name");
                        String servletName = servletnameElement.getStringValue();
                        // <servlet-class>server.LagouServlet</servlet-class>
                        Element servletclassElement = (Element) element.selectSingleNode("servlet-class");
                        String servletClass = servletclassElement.getStringValue();
                        // 根据servlet-name的值找到url-pattern
                        Element servletMapping = (Element) rootElement.selectSingleNode("/web-app/servlet-mapping[servlet-name='" + servletName + "']");
                        String urlPattern = servletMapping.selectSingleNode("url-pattern").getStringValue();
                        MyClassLoader myClassLoader=new MyClassLoader();
                        Class<?> aClass = myClassLoader.findClass(servletClass, path);
                        mapper.addMappedWrapper(path.split("webapps/")[1].toString()+urlPattern,(HttpServlet) aClass.newInstance());

                    }
                    mapper.addMappedContext(path.split("webapps/")[1].toString(),mapper.wrappers);;
                } catch (DocumentException e) {
                    e.printStackTrace();
                }

            }
        }
    }
    /**
     * Minicat 的程序启动入口
     * @param args
     */
    public static void main(String[] args) {
        Bootstrap bootstrap = new Bootstrap();
        try {
            // 启动Minicat
            bootstrap.start();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
